The invention relates to an apparatus and method for cooling the bearings of a godet for advancing and guiding an advancing yarn.
It is common to use, in particular in spinning machines operating at high delivery and takeup speeds, individual or groups of godets for guiding and advancing yarn, for example, in a draw zone. In this instance, the godets are typically equipped with an individual drive, which drives a shaft connected to a godet casing. Normally, the shaft is supported in a region between the godet casing and an electrical drive, such as is known, for example, from DE 37 01 077.
The currently attained yarn speeds of more than 1,000 m/min. require high-speed bearings which must operate at very high rotational speeds, and meet with an infinite service life. These enormous stresses lead to a relatively high heat energy in the electric drive as well as to a heating of the bearings. This gives rise to the problem that the operating temperatures of the bearings can be reached and exceeded very quickly.
In the known godet, the bearing bore is arranged directly in the wall of the machine frame that is constructed as a casing. However, this arrangement is not suitable for preventing the bearings from overheating.
EP 0 349 829 discloses a further godet, wherein the bearing housing is formed by a rotationally symmetric support. The support is arranged in a stationary housing. Likewise, this construction has the disadvantage that the heat generated in the bearing and emitted to the bearing housing can be dissipated only by heat conduction in a massive body.
The German Utility Model DE-GM 71 13 902 discloses a godet, wherein the bearings are cooled by air-cooled flow channels in the shaft and in the bearing housing. In this process, the air current is guaranteed by means of a fan wheel arranged on the shaft. This arrangement has the disadvantage that the hollow shaft must have a larger outside diameter in view of occurring stresses, so as to reach the strength of a solid cross section. However, this leads to still higher stresses of the bearings as a result of speed. A further disadvantage lies in the arrangement of the flow channels in the bearing housing. These flow channels do not facilitate an even radial heat dissipation.
It is accordingly an object of the present invention to further develop the above-described kind of a godet for advancing and guiding an advancing synthetic filament yarn such that the bearing housing facilitates a rapid and even heat dissipation from the region of the bearings.